US1862759A - Double lift single screw jack - Google Patents

Description

June 14, 1932. J. A. MORRISON I DOUBLE LIFT SINGLE SCREW JACK i Filed March 28, 1931 ad I; 3

3 .JA. Mrrzkap fl WM 7 5. 0 IW 2 2 .9. wax w height, at which Patented June 14, 1932 UNITED STATES some a monnrson', or WARREN, onro DOUBLE LIFT SINGLE SCREW JACK Application filed March 28, 1931. Serial No. 526,040.

The invention relates to lifting jacks such as are used for automobiles, trucks and other vehicles, and more particularly to a double lift jack provided with a single screw.

j J acks' of the type to which the invention peitains comprise two tubular lifting members adapted to be operated by a single lifting screw, one lifting member being raised, by means of the screw, to a predetermined point it is automatically locked to the other lifting member, which has been held against movement during this time, the second lifting member being-then automatically brought into engagement with the 5 lifting screw and raised to the limit of its movement, carrying with it the first lifting member which is locked thereto in extended position.

I am aware that attempts have been made in the past to produce acks of this type, and that patents have been obtained upon such jacks, but none of the jacks so produced or patented have proven commercially practical due to the locking means, for locking the two lifting members together, being insuflicient, and incapable of holding up under use. For this reason jacks of this type have never come into commercial use. 7

The object of the present improvement is to provide a practical, durable and efficient locking means for automatically locking the two lifting memberstogether at the desired point.

A further object is to provide such a looking means in the form of a collar which surrounds the inner lifting member and rests upon the upper end of the outer lifting member, means being provided upon said collar for engaging the lower portion of the inner member when it is raised to a predetermined height.

The above, together with other objects which will be readily apparent, from the ac- 3 companying drawing and the following detail description, or which will be hereinafter pointed out, may be attained by constructing the jack in the manner illustrated in the accompanying drawing, in which Figure is a vertical sectional view of the improved jack, showing the same in the lowered or collapsed position;

Fig. 2, a plan view of the improved locking collar;

Fig. 3, a top plan view of the housing within which the lifting members are normally contained;

Fig. 4, a sectional view of the upper portion of the housing taken substantially on the line inner lifting member with the locking collar in operative position, parts'being broken away for the purpose of illustration; and

Fig. 6, a vertical sectional view-of the upper portion of the outer lifting member, and the lower portion of the inner lifting member, 7 locked in extended position by the improved locking collar.

Similar numerals refer to similar parts throughout the drawing.

The jack may include the tubular housing 10, mounted upon the hollow base 11, which forms a gear housing for the bevel gear 12 and the bevel pinion 13 which meshes therewith. The gear 12 is axially fixed upon the vertical screw 14 and is mounted upon the so thrust bearing 15, of any suitable or desirable construction, located in the bottom of the. gear housing 11, and adapted to take the thrust of said screw under load.

The bevel pinion 13 is fixed upon the inner at end of the short shaft 16, which is journaled in the inclined bearing 17 and provided at its outer end with the usual socket or handle engaging portion 19 for engagement by the ordinary operating handle such as is commonly used for raising and lowering 'acks of this general type.

The tubular outer lifting member 20, is mounted for vertical movement within the housing 10, and is provided at its lower end with the nut portion 21, normally receiving the u-nthreadedportion 22 of the screw 14, when the jack is in the lowered position, as illustrated in Fig. 1 of the drawing.

For the purpose of preventing rotation of 1 the tubular member 20, when the same is moved vertically within the housing 10, studs 23 may be lined in the lower portion of said tubular n'icmber for sliding engagement in the vertical grooves 21 formed in the inner wall of the housing 10.

The inner lilting member 25 is also of tubular form and is slid able within the outer member 20, being provided, at its ower end, with the nut portion 26 normally engaged by the screw .14. Apair of diametrically opposed, longitudinal grooves 27 are formed in the inner tube 25, one of these grooves receiving the stud 28 projecting inward from the up per portion of the outer tubular member 20, to prevent relative rotation of the inner and outer lifting members.

The improved locking collar, which forms the principal feature of the invention, indicated by the numeral 29, and is of substantially the some inner and outer diamcters as the outer lifting member 20, upon the upper end of whi h the collar is located, surrounding the inner lifting member 25.

Studs 30 are diametrically located in the collar 29, and arranged to be normally received in the oppositely inclined grooves 31, formed in the interior of the upper portion of the housing 10. Inwardly disposed lugs 32., preferably equal in height to the collar, and tapered at their inner ends as shown in the drawing. are formed upon the interior of.

the collar and normally received within the vertical grooves 27 in the inner lifting mcm her. These lugs, as well as the studs 30, may be integral parts of the collar, which, for the purpose of strength. is preferably in the form of a drop forging.

Each of the grooves 27, in the inner lifting member, is provided near its lower end with an angular enlargement 33, arranged to receive the lugs 32, when the collar is turned to locking position, as illustrated in Fig. 5. Any suitable form of lifting cap, as shown at 34, may be provided upon the upper end of the inner lifting member, for engagement with the axle, spring, or other part of the vehicle to be lifted.

In the operation of the jack, assuming that the parts are in the normal, or lowered, position, as best shown in Fig. 1, the usual operating handle is connected to the socket 19, in customary manner, and rotated in the proper direction, whereby through the pinion 13 and gear 12 the screw 14 is rotated.

The outer lifting member 20 at first remains stationary, as the nut 21 thereof is not engagcd by the screw, but the nut 26 of the inner lifting member being in engagement with the screw will cause said inner lifting member to ride upward upon the screw.

As the inner lifting member is raised to a point where the stud 28 of the outer lifting member is engaged by the shoulder 35 at the lower end of the corresponding groove 27, the

outer lifting member will begin to rise with the inner member, moving the nut 21 thereof into engagement with the screw 14.

At the same time that the outer lifting member starts to rise, the collar 29 will be pushed upward thereby, and will be rotated by means of the lugs 30 passing upward through the inclined grooves 31 in the housing, moving the internal lugs 32 of the collar into the angular enlargements 33 in the lower portions of'the inner lifting member, thus locking the inner lifting member in extended position upon the upper end of the outer lifting member, before the nut 26 of the inner member passes upward out of engagement with the screw.

Further rotation of the screw will cause the outer lifting member to continue to rise until the studs 23 thereon contact with the upper ends 36 of the grooves 24, the inner member being carried upward in extended position upon the upper end of the outer lifting member.

In order to lower the jack the screw is 1'0- tated in the opposite direction, moving the nut 21 of the outer member downward until the studs 30 of the collar 29 are again received in the inclined grooves 31 of the housing, rotating said collar to move the lugs 32 thereof out of the enlarged angular pockets 33 and back into the grooves 27 of the inner lifting member, while at the same time the nut 26 of the inner lifting member is again moved into engagement with the screw 1%.

Immediately thereafter the nut 21 of the outer lifting member will be moved downward out of engagement with the screw, the outer lifting member returning to the position shown in Fig. 1. The inner lifting memher will then continue to descend until it also returns to the position shown in Fig. 1.

I claim:

1. A lifting jack including a housing, a screw within the housing, means for rotating the screw, a pair of tubular lifting members normally telescoped within the housing, nuts upon said lifting members for engagement with the screw, a collar at the upper end of the outer lifting member, and means for automatically locking said collar to the inner lifting member when said inner lifting member has been raised to a predetermined point.

2. A lifting jack including a housing, a screw within the housing, means for rotating the screw, a pair of tubular lifting members normally telescoped within the housing, nuts upon said lifting members for engagement with the screw, a rotatable collar at the upper end of the outer lifting member, and means for automatically rotating said collar for locking said collar to the inner lifting member when said inner lifting member has been raised to a predetermined point.

3. A lifting jack including a housing, a screw within the housing, means for rotating the screw, a pair of tubular lifting members normally telescoped within the housing, nuts upon said lifting members for engagement with the screw, a collar at the upper end of the outer lifting member, and means upon the collar and housing for automatically locking said collar to the inner lifting member when said inner lifting member has been raised to a predetermined point.

4-. A lifting jack including a housing a screw within the housing, means for rotating the screw, a pair of tubular lifting members normally telcscopcd within the housing, nuts upon said lifting members for engagement with the screw, a rotatable collar at the upper end of the outer lifting member, and means upon the collar and housing for automatically rotating said collar for locking said collar to the inner lifting member when said inner lifting member has been raised to a predetermined point.

ii. A lifting jack including a housing, a screw within the housing, means for rotating the screw, a pair of tubular lifting members normally telescoped within the housing, nuts upon said lifting members for engagement with the screw, a rotatable collar at the upper end of the outer lifting member, and coacting studs and inclined grooves in the collar and housing for automatically rotatthe collar for locking the collar to the inner lifting member when said inner lifting member has been raised. to a predetermined point.

A lifting jack including a housing having inclined grooves therein, a screw within the housing, means for rotating the screw, a pair of tubular lifting members normally telescoped within the housing, nuts upon said lifting members for engagement with the s ew, a rotatable collar at the upper end or the outer lifting member, and studs upon collar for engagement with the inclined s in the housing for automatically the collar for locking the collar to ier lifting member when said inner member has been raised to a predeliftingjaclr including a housing, a

screwwiuain the housing, means for rotatthe screw a pair of tubular lifting memnuts upon said lifting members for engagemeat with the screw, the inner lifting memb ing longitudinal grooves provided 'ar portions near their lower ends,

hers normally tale-scoped within the housing,

ing the screw, a pair of tubular lifting members normally telescoped within the housing, nuts upon said lifting members for engage ment with the screw, the inner lifting member having longitudinal grooves provided with angular portions near their lower ends, a rotatable collar at the upper end of the outer lifting member, lugs upon said collar for engagement with said grooves, and means upon the collar and housing for automatically rotating said collar to move the lugs into the angular portions of the grooves when the inner lifting member has been raised to a predetermined point.

9. A lifting jack including a housing, a screw within the housing, means for rotating the screw, a pair of tubular lifting members normally telescoped within the housing, nuts upon said lifting members for engagement with the screw, the inner lifting member having longitudinal grooves provided with angular portions near their lower ends, a rotatable collar at the upper end of the outer lifting member, lugs upon said collar for engagement with said grooves, and coacting studs and inclined grooves in the collar and housing for automatically rotating said collar to move the lugs into the angular portions of the grooves when the inner lifting member has been raised to a predetermined point.

In testimony that I claim the above, I have hereunto subscribed my name.

JOHN A. MORRISON.

le collar at the upper end of the I

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